Cooling towers are heat exchangers of a type widely used to emanate low grade heat to the atmosphere and are typically utilized in electricity generation, air conditioning installations and the like. In a mechanical draft cooling tower for the aforementioned applications, airflow is induced or forced via an air flow generator such as a driven impeller, driven fan or the like. Cooling towers may be wet or dry. Dry cooling towers can be either “direct dry,” in which steam is directly condensed by air passing over a heat exchange medium containing the steam or an “indirect dry” type cooling towers, in which the steam first passes through a surface condenser cooled by a fluid and this warmed fluid is sent to a cooling tower heat exchanger where the fluid remains isolated from the air, similar to an automobile radiator. Dry cooling has the advantage of no evaporative water losses. Both types of dry cooling towers dissipate heat by conduction and convection and both types are presently in use. Wet cooling towers provide direct air contact to a fluid being cooled. Wet cooling towers benefit from the latent heat of vaporization which provides for very efficient heat transfer but at the expense of evaporating a small percentage of the circulating fluid.
To accomplish the required direct dry cooling the condenser typically requires a large surface area to dissipate the thermal energy in the gas or steam and oftentimes may present several challenges to the design engineer. It sometimes can be difficult to efficiently and effectively direct the steam to all the inner surface areas of the condenser because of non-uniformity in the delivery of the steam due to system ducting pressure losses and velocity distribution. Therefore, uniform steam distribution is desirable in air cooled condensers and is critical for optimum performance. Another challenge or drawback is, while it is desirable to provide a large surface area, steam side pressure drop may be generated thus increasing turbine back pressure and consequently reducing efficiency of the power plant. Therefore it is desirous to have a condenser with a strategic layout of ducting and condenser surfaces that allows for an even distribution of steam throughout the condenser, that reduces back pressure, while permitting a maximum of cooling airflow throughout and across the condenser surfaces.
Another drawback to the current air cooled condenser towers is that they are typically very labor intensive in their assembly at the job site. The assembly of such towers oftentimes requires a dedicated labor force, investing a large amount of hours. Accordingly, such assembly is labor intensive requiring a large amount of time and therefore can be costly. Accordingly, it is desirable and more efficient to assemble as much of the tower structure at the manufacturing plant or facility, prior to shipping it to the installation site.
It is well known in the art that improving cooling tower performance (i.e. the ability to extract an increased quantity of waste heat in a given surface) can lead to improved overall efficiency of a steam plant's conversion of heat to electric power and/or to increases in power output in particular conditions. Moreover, cost-effective methods of manufacture and assembly also improve the overall efficiency of cooling towers in terms of cost-effectiveness of manufacture and operation. Accordingly, it is desirable for cooling tower that are efficient in both in the heat exchange properties and assembly. The present invention addresses this desire.
Therefore it would desirous to have an economical, mechanical draft, modular cooling tower that is efficient not only in its heat exchange properties but also in its time required for assembly and cost for doing the same.